Brake



May 21, 1940.

D. HOPPENSTAND BRAKE Filed Sept. 29, 1937 2 Sheets-Sheet 1 INVENTORDavid Hoppensi'and M y 21, 1940- --D. HOPPENSTAND 2,201,293

BRAKE Filed Sept. 29, 1937 2 Sheets-Sheet 2 j-ZZ 221 INVENTOR DavidHoppenstand Patented May 22, l

NETED STATES PATENT OFFICE 2 Claims.

This invention relates to brakes and, in particular, to a brake which iswell suited for automotive vehicles although not limited to thatspecific field, having numerous other applications as well.

Automotive brakes as most widely used at present comprise a pair oflevers pivoted at one end on a fixed member and adapted to be forcedoutwardly into engagement with the interior of a brake drum to which thevehicle wheel is secured. Brakes of this type usually require the use ofbrake lining on the pivoted levers, and this lining must be replacedwhen worn. It is usually secured to the brake levers by rivets. Thelatter are objectionable because they score the drum when the lining isworn down. Since the pivot on which the brake levers turn is fixed, onlya relatively small portion of the area of the lining has effectivebraking engagement with the drum. This limits the braking action whichcan be exerted.

I have invented a novel form of brake which is particularly adapted forautomotive use although it may be applied as well to rail cars,industrial applications, etc. In accordance with my invention I providebrake levers pivoted adjacent their mid-point and provided with shoesadjacent their ends for engagement with theinterior and exteriorrespectively of a brake drum. This construction is characterized bynumerous advantages over that now most widely used. These advantageswill become apparent. as the description of the invention proceeds. Atypical embodiment of the invention is illustrated in the accompanyindrawings, although it is to be understood that it may also be embodiedin forms other than that shown. In the drawings:

Figure 1 is a sectional view taken on a plane perpendicular to the axisof the brake drum and just inside the disk portion of the drum;

Figure 2 is a sectional view taken on the line 11-11 of Fig. 1; lineI--I of Fig. 2 indicates the plane on which the section shown in Fig. 1is taken;

Figure 3 is a side elevation of a brake lever according to my invention;

Figure 4 is an end view as would be seen by looking from the left inFig. 3;

Figure 5 is an end view such as would be seen by looking from the rightin Fig. 3;

Figures 6 and 7 are similar to Figs. 3 and 4 showing anothermodification of the invention;

Figure 8 is a view similar to Fig. 5 showing further modification.

55 Referring now in detail to the drawings, Figs.

1 and 2 show the brake incorporated in the front wheel of an automotivevehicle. A supporting plate or brake mounting disk It is secured to asteering knuckle II in any convenient manner and is provided withbearings 2 for the wheel spindle (not shown). In the case of the rearwheels, the plate i is secured to the end of therear axle housing.

A brake drum I3 has a rim portion l4 and a hub portion l to which awheel (not shown) is 19 removably secured, by bolts for example.

Brake levers l6 are pivotally mounted intermediate their ends on pins I!having threaded ends extending through holes in the plate In for thereception of nuts Ila. The levers I6 consist generally of a flatplate-like portion l8 and shoes I9 and 20 upstanding therefrom adjacentthe ends of the levers. These shoes may be formed integral with theplate-like portion of the levers or may be separately formed andattached thereto as by rivets or the like.

The shoes I9 are adapted to engage the interior surface of the rim ll ofthe drum I3. The shoes 20 are similarly adapted to engage the exteriorsurface of the drum. The shoes may be of any desired metal. Inaccordance with a modification of my invention shortly to be described,the shoes may also be of non-metallic material.

Brake lever actuating means 2| in the form of a hydraulic cylinderhaving twin pistons reciprocable therein, is provided for effectingangular movement of the levers Hi to cause engagement of the shoes l9and 20 with the drum. Brake actuating devices such as indicated at 2|are well known so that no specific description of the latter isnecessary. A connection 2la carried by the cylinder provides for theattachment of a conduit leading to any suitable pressure generatingsystem. The pistons reciprocable in the cylinder 2| have fingers 22thereon with 0 rounded outer ends seated in recesses 22a formed in theshoes Hi. It will be clear from the construction so far described thatthe admission of fluid under pressure, to the cylinder 20, causes thefingers 22 to move outwardly and force the shoes l9 against the interiorof the drum I3. The shoes 20 simultaneously engage the exterior of thedrum. A tension spring 23 retracts the brake levers to their illustratedpositions upon the release of the pressure in the cylinder 20, thusreleasing the brakes.

Referring now more particularly to Figs. 6 and 7, a brake lever 25 thereshown, is similar to the levers It in general but is provided withpockets 2G and 21 adjacent its ends. The pockets 26 and 21 are adaptedto receive separately formedbrake shoes or blocks 28. The blocks 20 maybe of hard carbon or other similar material and'are secured in theirpockets by rivets 29 extending through the side walls of the pockets.

A further modification is shown in Fig. 8, and comprises a lever 30similar to those shown at It except that the shoes l9 and 2|! areadapted to receive brake lining segments 3|. Rivets 32 secure the liningsegments 3| to the shoes.

The advantages of the invention will be largely apparent from theforegoing description. In the first place, the engagement of the brakedrum exteriorly and interiorly by the shoes carried on my center pivotedbrake levers aflords a braking action much more positive and effectivethan can be secured with brakes of the construction previously employed.The combined eflect oi the interior and exterior shoes is to seize thedrum and exert a powerful retarding action thereon. Special surfacingmaterial for the brake shoes may be dispensed with although it may beemployed, if desired, as shown in Fig. 8. The brake shoes thus may bemetallic or nonmetallic and in either case are characterized by longlife without the necessity for frequent replacement.

A further advantage of the invention is that it is self adjusting, anywear on the brake shoes being immediately taken up by increased movementof the actuating mechanism.

A further advantage of the construction described is that it may beincorporated in vehicles with little or no change, and requires almostno departure from manufacturing practice which is an accepted standardin this held. The invention is also characterized by greater quietnessof operation than previous brakes. The construction, furthermore, is assimple as or simpler than that of brakes used heretofore for similarapplications.- I

While I have illustrated herein but a preferred embodiment of theinvention with certain modifications, it will be understood that changesin the construction disclosed may be made without departing from thespirit of the invention or the scope of the appended claims.

I claim:

1. A brake comprising a fixed support, a brake drum mounted for rotationadjacent said support, brake levers pivoted on said support adjacentsaid drum and on opposite sides of the axis of rotation thereof, shoeson said levers overlying the inner and'outer surfaces of said drum,

.the shoes which overlie the inner surface ofthe drum being disposedadjacent each other, and extensible means disposed between and abuttingboth the last-mentioned shoes.

2. A brake comprising a fixed support, a brake drum mounted for rotationadjacent said support, brake levers pivoted on said support adjacentsaid drum and on opposite sides of the axis of rotation thereof, shoeson said levers overlying the inner and outer surfaces of said drum, saidlevers being so disposed that the shoes which overlie the inner surfaceof the drum are adjacent each other, and extensible means between saidlast-mentioned shoes eflfective to force them outwardly against thedrum.

DAVID HOPPENSTAND. a

